Accumulator



A. BERGER 2,450,031

ACCUMULATOR I5 Sheets-Sheet 1 sept. 2s, 1948.

Filed Jani 50, 1945 ow\ m; QS. QS 93mm on 1 I/ ov v n Nv 1 Il! .u m T!i u v w Q m mm m QSG QEQQ Bk @S552 Smmm mnwwmq Sq N I N V EN TOR. imm/vans 551e @se BY A a@ M i.;

Sept. 28, 1948. A. BERGER 2,450,031 A ACCUMULTOR Filed Jan. so, 1945 s sheets-sheet 2 INVENTOR. LExA/vef Bfase.

' A. BERGER Sept. 28, 1948.

ACCUMULATOR 3 Sheets-Sheet-` 5 Filed Jan. 30, 1945 Patented Sept. 28, 1948 v ACCUMULATOR Alexandre Berger, New York, Y.,a ssignor1.tn

AircraftHydraulics2 Inc., acorporationof lljenr` York Application January 30, 1945,5Seri'al-No. 5752330 Thisinvention-relates to improvements inaccumulators and has for its main object the pro vision of :an accumulator including a piston aand azlongitudinal expansible member having oneend secured-to said pistonand the other endsecured inlfluid tight relation to one .endof the cylinder in which :said piston operates.

-Another `ulriect'of the invention is the'provision man-.accumulator employing acylinder having. afpistonand a longitudinally expansibleznembei' between the piston and one end of the cylindensaidexpansiblemember including side Walls which Iareiormed1.0i a series oivannular plaits, Whichfoldfupon one another whensaid expan'sible memberis collapsedl said expansible-*member-also having in cooperation with the interior thereof a tubular'wall secured to a head of the cylinderv and serving as a. guide forvsaid plaits as they approach the point where the plaits are collapsed upon each other.

Yet another object of the invention is the: provision oiamaccumulator including av cylinder havingaplstonoperable therein and flexibly con,- nected bfymeansofa greatly expansiblemember in ffiiuid tight relation to one end constituting the lhead oiqsaid cylinderrtubular guide-means within said expansible member including -a perfora-te lar diaphragmformedofv natural or articial-rube ber compounds and having its Walls formedv with ase-ries o'ffinwardly extending peaks andV out- Hardly )extending peaks alternately disposed, the materialzin'said peaks beingthinn'er than the ma- 11V Claims. (CL, 1385-311 terialioi'ningfsaid peaks', thereby permitting said `2. I v V'FigureZ islafsectional evation of .one former my new and improved accumulator;

AFigure 3 is aview oithey piston .employed in the accumulator of vFigure v 2, showing clearances whichl permitvtheair to passby. the piston and contact the expansible element;

.Figure 4. is a sectionall elevationoi amodified form of-the accumulator; n

Figure 5v .is ya plan .view .of the accumulator shown in Figure 4; gand Figured-isa cross .sectional view as seen along the lnesznlL-.ofEigure 4. f .Y

.Referring .,rst to Fig-2, Ythe accumulator inu cludes -a --cylinder I ll fhaving its upper end internally threaded ,at ll and Vhaving external threaded-2 ,formed on the other end. The lower end of the cylinder and arcuatevstep i3 is formed for apurposewhich lvvill presently be described. The lower end oi the-'cylinder is provided `with a head .A lll-.by havingfan annular flange f I 5 which isv internally threadedto match .the threads. l2, formed on the cylinder'. The cylinder head .Mis provided .with a bossll having `a central hole .il Whichis Vthreadeclto accommodate a pipe, ortting. Mounted ,onthe cylinder head is a cup member. i8; theil'ower end.k la. oi-whichhas a. hole Ztl' formed .therein communicating with. the hole ll. -Thecupmaylbesecured to the cylinder head in any suitable-manner, for example, by means V.of screws 2l. Theupper--end of the. cupis open.

Mounted. in the cylindeialv isa deformable member Agenerally.designated by the numeraLZS. The. side. walls-.of the deformable member 23- are preferablyiormed vof artificial rubber, or thelike, andconstitute a--series oiannular .-plaits or folds, -which are Lthinnedin ,the interiors of the internal apexes ,24, yand in the interiors .of ltheexternal apexes 25,; so that vWhenthe element .Z3-.s entirely 'collapsed the Vfolds will lie. upon one another. The exteriors 26 oijthe internal apexes lie along a circular line clearing the-exterior of the cup member i8. The exteriors of the .external apexes 12.1 lie valong a'lineclearlng .the interior "bore oi the cylinder IU. Continuous with, or joining the Upper foldLorplait'is a web 28 to which isy secured in any suitablek manner apiston 30 which hasa series of arcuateslots 29 formed therein rtapermit air from the chamber 3l in the cylinder above thepistonto communicate with the .exterior oi the-'.deformableelement 23f Thelower end V32 of thedeform-able .element 23 extends beyond the diameter of the element. proper and is .finished with' an arcuaterim33 which is engaged bythe arcuate (groove I3V to. form arluid tight seal be,- tweenfthelowerend of vthe vcylinder and the deformable element. A suitable insert 34 may be formed in the material to stiffen the portion 32.

The upper end of the cylinder is provided with a head or plug 35, the outer diameter of which is provided with threads which engage the threads After the plug 35 is screwed into the cylinder it may be soldered or brazed, at 36, to form a fluid tight seal. The plug 35 may have a central threaded hole formed therein to accommodate a fitting such as that shown at 31. The fitting 31 may be connected to a source of air pressure and a pipe or fitting engaging the threaded hole |1 may be connected to and receive oil from any hydraulic system in which the accumulator is to be used. p

Referring now to Fig. 1, which is a diagrammatic representation of an hydraulic system showing one example of the use of my new and improved accumulator, the threaded hole I1 is connected to the system and the fitting 31 is connected to a source of air under pressure, the pressure of which has a definite relation to the hydraulic pressure in the system. lThe system includes a reservoir 38 for the oil, and this reservoir is connected both to a check valve 39 and to a pump 40 which may be either a hand pump or a power driven pump. The check valve 39 is connected to the point 42 on a two-way selector valve 4|. The outlet of the pump 40 is connected viava check valve 43 to the point 42 and also to the fitting |1 on my accumulator and to a pressure gauge 44. The outlet of the pump 49 is also connected to a pressure relief valve 45. vAn actuating cylinder 46 has a piston rod 41 which may be operatively connected to any means to be actuated. One end of the actuating cylinder is connected to the-point 48 on the selector switch and the other end of the cylinder is connected to the point 49. When the actuating switch is in the position shown in the diagram, oil, under hydraulic pressure, is delivered to the end 46a of the cylinder 46, and this pressure acting upon the piston in the cylindercauses the piston rod to move to the right vas seen in Fig. 1. As the piston moves to the right, as just described, oil in the end 4Gb of the cylinder is forced out and passes via the point 48 on the selector switch to the point 50 and thence via the return line (shown dotted) to a filter and thence into the reservoir 38. When it is desired to move the piston rod 41 in the opposite direction the selector valve 4| is thrown to its otherposition to supply oil under pressure via the point 48 to the end 46h of the cylinder. As the piston moves to the left the oil in the end 46a is forced out and passes via the points 49 and 59 on the selector valve and thence via the filter 5| to the reservoir 38. The difference between the hydraulic pressure of the air pressure effects the accumulator action. Obviously the accumulator may be used in other systems than the one shown in Fig. 1, and the arrangement shown in Fig. 1 is merely anexample.

Referring now to Figs. 4, 5, and 6, a cylinder 52 has an interior bore 53 which has a Istep 54 formed therein the purpose of which will presently be described. The upper end of the cylinder 52 has a boss 55 formed thereon and this boss has a central hole 56 formed therein the outer end of which is provided with threads 51 to accommodate a fitting.

Within the cylinder 52 is a piston 58 which carries a boss 59 the upper end 6D of which is curved to conform to the dome-shaped end 53a of the interior of the cylinder. AV closure plate or head 6| has a counterbore 62 formed therein to accommodate the flange 63 which is formed integral with the cylinder 52. Within the cylinder is a deformable member generally designated by the numeral 64. The bottom end 65 of the deformable member is flanged upwardly and lies within the step 54 and includes an upper surface which is beveled. Mounted upon the flange and also lying within the' step is an annular pressure ring 66. The thickness of the iiange 65 and the ring'is greater than the depth ofthe step 54 so that Whenrthe bolts 61 securing the cylinder to the head are tight a iiuid tight yseal is effected between the flange 65 and the head 6|. The side walls of the deformable member 64 constitute a series of annular plaits or folds which are thinned in the interiors of the internal apexes 68 and also in the interiors of the external apexes 69, so that when the element 64 is entirely collapsed the folds will lie substantially upon each other. The apexes 69 lie along a circular line clearing the exterior of a cylindrical member 18 and this cylindrical member, among other things, functions as a guide for the plaits or folds of the member 64 when it is tight and Vapproaches the collapsed position. The cylinder member may be secured to the plate 6| in any suitable manner, for example, by means of screws 1|. The upper end 12 of the member 1|] is closed except for a plurality of performations 13 formed therein, the functions of which will presently be described. The deformable member 64 has its upper lend closed by means of a web 14v formed integral therewith and this web is in turn secured to the piston 58 in any suitable manner, for example', by means of screws 15, passing through a reinforcing plate 16. The piston 58 may have a plurality of grooves 11 formed therein to permit air to pass from the upper portion of the cylinder to the outer walls of the deformable member 64. The plate 6| has a plurality of holes 18 formed therein and communicating with the interior of the member 19.

A second cylinder 88 has an interior bore 19 and an annular flange 8| formed integral therewith. The plate or head 6| has a second counterbore 82 formed' therein to accommodate the flange 8| so that the cylinder 89 will be properly located thereon. Suitable sealing means 83 in the form, for example, of an annular packing positioned in a groove formed in the plate 6| may be provided. A boss 84 formed on the body of the cylinder 80 has a threaded hole 85 formed therein to accommodate a fitting, and a passage 86 formed in said boss and the flange 8| communicates with a milled Vpassage 81 formed in the plate 6|. The passage 81 communicates with the interior 19 of the cylinder.

A piston 88 within the bore 19 carries a suitable vpacking ring 89 which engages and effects a seal with the wall of the cylinder bore 19. A piston rod 9D is operatively connected to the piston 88 and passes through a hole 9| formed in the cylinder body concentric with the bore 19.

A connection is made to the threaded hole 85 so that a fluid medium, oil, for example, lmay be forced into the cylinder bore 19. The oil passes through the passage 86 and the milled groove 81 and thence into the interior. As the cylinder fills some of the oil then passes via the holes -18 into the interior of the member 10 and thence passes via the holes 13 into the interior of the deformable member 64. When the device is properly charged with oil the hole 85 is sealed with a plug or the like. Air from a source of air under pressure Vis connected to the upper end of the cylinder 52.

When the piston rod 90 is connected to a device, for example, the shock absorbers on airvv mit, sand.. isaid; aircraft; lis going-vandalici; a the shock othewheels mee ne'th theffpistonn-iupwardw: ..Iiilsfc t from-fthe;,bylinderx wia; the (holes. interiorzoffithe limembers- Dnc tn: thensudden tendency fof. thez-.oil to, 1passi .fromxithe clylinder 80 into saidzinterion: thednoies 1B i fwhichianeqsmall; fwire draw theoil-rand: its passage therethrough isisomewhatzretarded.. {Oilsgfromfthe interiorzfof the member-10, lnpassingz--tos.thepinterior ofthe deformalilczmember: 64; wire" .drawr1."f as iti-:passesithroueh` the holewla'. the shock; isgof greatrextentqconsiderable oil4 ill passafromrthe cylindien lin-to the :deformable :Lmiember Git Vand the l,pisttin 1 5= will bei miiisedfto moveA upwardly against the; airpressimei whichiisnuppiied: to interioricf,thecylindenz;i y ,Y l

From; the above-;description. it #will beseen:that my methodbVl y.causing :the fsislook tto fiom@ Oil throughseveralI series of: small..ho1es :orfperforations anddeliveringtheoverflow or'oil jiwhere'the .areof :substantial:` force)` inte` lthe interior ofitherdeformable "memberfthefexterior: or the s deformablefmembei-.being subjectedrtofair pressure, constitutes iwhat .1; believesrto-fbe -inew .and Vsnovel minieme.. l i y i' I have: fhereinrV-sliown @amddescribed bysway orexample'tworormsof the inventiomit isa` yobvious.that; manyavariationsi may; be madein thefffarrangements herein ,shown and described tiu'tlmutz, departing frcm.gth e spirit, of' ;theinven tiernas set;.forth following sciaims.

is-.claixned;.is:

v .i1...-`In. anaccumulatorpa closedl cylinder-adapted toi-have its closed endl connected toga sourceof fluid ymediunrilunxler pressure .fandhavirrg acylinder head detachably secured to its otherrenid andfa'dapted to be connected to a difierent source of fluid underfpressureL a'piston in said cylinder having clearance passagesl lformed therein, and an elongated expansible. :and veontractible nonmetallic member having one end .Y flanged and secured iniiuidtightrelation between said other end of saidcylinder and `said cylinder head, the othenrend of said expansiblefg; and contrafotble member r,being ,closed- ,and formed integral therewithaidgclosedend of saidmember beingsecuredlto andaguidedby said pistom saidexnansible and contractible membenhaving its exterior subjected to the pressure of `fluid' from said iirst mentioned source and having its interior sub-- jected'toluid. pressure from. saidv secondmentioned source.

2. In an accumulator, a closed cylinder adapted to have one end thereof connected to a source of air under pressureand having its other end adapted to be connected to a source of liquid under pressure, a piston in said cylinder having clearance passages formed therein, a nonmetallic expansible and contractible member having one end closed and the other end forming an annular flange, means for securing said flange in fluid tight relation to said second men tioned end of said cylinder, guide means comprised of an open-ended cup within said mem ber concentric with said cylinder, other means securing said closed end to said piston, the walls of said member being circular and formed of a plurality of alternate inwardly and outwardly extending annular folds or pleats, a passage through the bottom of said cup adapted to be connected to said liquid under pressure, said member having its interior subjected to said liquid under pressure and having its exterior under the influence of air under pressure.

Cil

d. accumulatona-closed;cylindenadapted; to ,hauei one 1 end thereof connected to 'a source ofsairunder pressure `an'dfhaying its otherend adaptedtoifbe: connected vtol-a source ,of-liquid under: pressure, a piston.y in said cylinder having clearance Y passages formed therein, a "remove/'bie cylinder -head iforming a closure Vfor said- 4.other end of'isaid cylinder, a flexible non"metallic-'exil pansi-blei-:and' contractible member :having one end'closed` and the other' end forming an annular Hange, cooperative` means l partlyk onv said cylinder head andpartly .onsaid other end'ofv said cylinder for-securing. said flange. in uuid tight relation to saidsec'ond mentioned end offsaid cylinder yand means securing .said closed end to sai-d1 piston;v the ywalls ofv said member being circular and formed of a plurality of alternate inwardlyandoutwardly extending annular' folds or pleats', said member 'having its interior subjected' to said liquid under vpressure and having its exterior under 'the influence of air under'pressure,`and an open ended cup positioned in saidcylinder and having its. closed end secured to` -said cylinder head, said cup `lying within and serving as a guide forthe inner folds orpleat-sfof said member fas the latter approaches itsnormal-or collapsed position.

4. In -an accumulator, a cylinder, alchamber in said cylinder carrying a' iiuid=under pressure, anelongated -expansible and ccntraictible niember having one end in fluid tightv relation tothe end-of said cylinderand defining said chamber', saidmember beingV formed of rubber or'theliiie and having its wall formed of avplurality` of alternate inwardly and outward-ly extendingffolds or pleats, the other en'dof y,sa-id-meniber being closed and formed integral therewith, 'afpiston insaid; cylinder securedto the closed end of said member andvserving as a guide for said vvend ef said member, an open cup forming interior-'guide means for said member, said'cup'beingmounted on the end of and concentric-with said-cylinder', and means for connecting cylinder to-a lsource of compressed air; 1

` 5."In an aecul'nulator,Y'acylinder positionedi-inontactlwit-h one -face-oi a plate forming Ya 'cyit inder headjza' second-cylinder secured tothe op-` posite face of said plate and preferably lhavin-g its bore inali'gnmen-t lwith thebore lorsa'i'd first f cylinden'ajpiston vin saidsecond cylinder, anonmjetallic eniongated expansibl'e member mounted in saidV first lcylinder andhaving its llower 'endv secured in Iiuid tight relation to said cylinder and having its other end secured to said piston,

Ameans for connecting said first cylinder to a source of compressed air, means for lling said second cylinder with a liquid under pressure, and means in said head providing communication between said second cylinder and the interior of said chamber.

6. An accumulator according to claim 5 in which said means in said head providing comn munication between said second cylinder and the interior of said expansible member comprises a plurality of small holes tending to wire draw the liquid passing from said cylinder to said interior.

7. In an accumulator, a cylinder positioned in contact with one face of a plate forming a cylinder head, a second cylinder secured to the opposite face of said plate and preferably having its bore in alignment with the bore of said rst cylinder, a piston in said second cylinder, an expansible and contractible member having one end closed and the other end forming an annular flange which is clamped in fluid tight relation between said rst cylinder and said cylinder head, the walls of said member being circular and formed of a plurality of inwardly and outwardly disposed folds or pleats, a piston in said rst cylinder secured to the closed end of said member, a closed ended cylindrical guide secured to said head and positioned Within `Said expansible member, a plurality of perforations formed in the closed end thereof, other perforations providing communication between said second cylinder and the interior of said cylindrical member, means for connecting said iirst cylinder to a source of compressed air, and means for filling said second cylinder, said cylindrical member and the interior of said expansible member with a fluid under pressure and sealing the same therein.

8. An accumulator according to claim 7 in which said cylinders are provided with flanges and in which the cylinder head has annular depressions formed on opposite faces thereof into which said flanges may seat, said cylinder head also having an annular V-shaped groove formed therein to contain packing for effecting a seal between said second cylinder and said headV 9. In an accumulator, a cylinder having `a piston reciprocable therein, a piston rod secured to said piston, a head for said cylinder, said head having a groove formed therein providing a passage communicating with the bore thereof, a longitudinal hole in the wall of said cylinder substantially parallel to the bore thereof and a radial hole extending from outside said cylinder into the wall thereof and communicating with one end of said longitudinal hole, the other end of said longitudinal hole registering with said groove, whereby said groove and said holes conjointly provide communication between the ex terior of said cylinder and the interior thereof, and threads formed in the outer end of said radial hole to accommodate a fitting for lling said cylinder with fluid under pressure and sealing the same therein.

10. In an accumulator, a cylinder having a piston reciprocable therein, a piston rod secured to said piston, a head for said cylinder, means forming a passage between the exterior of said cylinder and the space between said piston and said cylinder head, a second cylinder secured to the opposite face of said cylinder head, an elongated expansible and contractible member having one end in iiuid tight relation to the end of said secondA cylinder and dening alluid chamber, the other' end of said member being closed, a piston in Said second cylinder secured to the closed end of said member and serving as a guide for said member, and a plurality of small holes in said cylinder head communicating with the interior of said first cylinder and the interior of said member, said small holes tending to wire draw liquid passing from said cylinder to theinterior of said member.

11. In an accumulator, a cylinder having ra piston reciprocable therein, a piston rod secured to said piston, a head for said cylinder, a radial groove formed in said cylinder head and having one end'thereof communicating withthe interior of said cylinder, a longitudinal hole formed in the wall of said cylinder and having one end communicating with said groove, va radial hole extending from outside said cylinder into the Wall thereof and communicating with said longitudinal hole whereby said groove and said holes conjointly form a passage between the exterior of the cylinder and the interior thereof, a second cylinder secured' to the opposite face of said cylinder head, an elongated expansible and contractible member having one end in fluid tight relation to the end of said second cylinder and deiining a fluid chamber, the other end of said member being closed, a piston in Vsaid second cylinder secured to the closed end of said member and serving as a guide for said member, and a plurality of small holes in said cylinder head communicating with the interior of said first cylinder and the interior of sai-d member, said small holes tending to wire draw liquid passing from said cylinder to the interior of said member.

ALEXANDRE BERGER.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 1,950,107 Guilin et a1. Mar. 6, 1934 2,341,556 Joy Feb. 15, 1944 2,365,994 Ashton Dec, 26, 1944 FOREIGN PATENTS Number Country Date 683,936 Germany Oct. 26, 1939 

